Clinical and radiologic features of lumbar spinal stenosis and disc herniation with neuropathic bladder

Study Design. Clinical and radiologic findings of patients with lumbar spinal stenosis and lumbar disc herniation presenting with neuropathic bladder were prospectively analyzed. Objectives. To study the relationship between the degree of cauda equina compression and prevalence of neuropathic bladder in patients with lumbar spinal stenosis and lumbar disc herniation. Summary of Background Data. Bladder dysfunction has frequently been noted in patients with lumbar spinal stenosis and lumbar disc herniation. However, there have been few studies that have demonstrated the correlation between bladder function and the degree of stenotic compression of the cauda equina seen on radiologic findings in patients with lumbar spinal stenosis and lumbar disc herniation. Methods. Thirty-four patients admitted for treatment for lumbar spinal stenosis or lumbar disc herniation underwent urodynamic studies, and computed tomographic scans after myelography were obtained to determine the degree of cauda equina compression. The cross-sectional area and anteroposterior diameter of the dural sac were measured at their smallest transverse area. Results. Twenty (58.8%) of the 34 patients were diagnosed with positive neuropathic bladder. There was no significant difference in the cross-sectional area of dural sac between the patients with positive neuropathic bladder and with negative neuropathic bladder. However, the dural sac anteroposterior diameter in positive neuropathic bladder patients was significantly shorter than that in patients with negative neuropathic bladder. A critical size for the dural sac of patients with neuropathic bladder was revealed as 8 mm in this study. Conclusions. The prevalence of neuropathic bladder is more significantly associated with dural sac anteroposterior diameter than with the cross-sectional area of dural sac. Therefore, dural sac anteroposterior diameter might be an important factor predicting the existence of neuropathic bladder.